A number of single-use flossing devices are know and commercially available. Such devices typically have a floss holder that includes two spaced-apart arms extending upwardly, or outwardly, from a base to form a generally U-shaped configuration with the floss attached at each end to one of the arms and spanning the distance between the spaced-apart arms. The devices also include a handle portion in association with the floss holder.
In some devices, the dental floss holder itself is removable from the handle portion and thus replaceable. Such devices generally include a handle with a head portion designed to receive and hold the dental floss holder. In use, the dental floss holder is attached to the head portion of the handle and the floss is inserted between teeth. After flossing, the dental floss holder is removed from the head of the handle and replaced with a new dental floss holder. Such devices are shown in, for example, U.S. Pat. Nos. 5,483,982, 7,059,334, 7,174,904 and 7,325,554, the content each of which is hereby incorporated by reference in its entirety. It is noted that devices exemplified in such patents and commercial products made according to the disclosures of such patents do not use wax coated yarns. In other devices, the dental floss holder is integral with the handle portion to form a unitary device, such that the entire device may be disposed of after completion of flossing.
In one method of manufacturing such devices and attaching the floss to the arms of the floss holders, the floss holder, whether removable from or integral with the handle, typically is molded from plastic around the uncoated floss to provide the generally U-shaped floss holder having the floss attached to and extending between the spaced-apart arms of the holder. As noted, holders may be molded integral with a handle portion to form a unitary device, or may be molded with means to rigidly connect the detachable floss holder to the head of a handle which is configured to receive the detachable floss holder.
Flosses in general must be capable of passing between several teeth without significant fraying or breaking during insertion of the floss between the teeth and also during the up and down motion of the flossing process. For this reason, some yarns are made from an extremely strong material, such as ultra high molecular weight polyethylene (UHMWPE). Furthermore, multifilament yarns that are highly twisted, i.e. having more than two turns per inch, to hold adjacent fibers, or filaments, tightly together during the flossing process also are used. Twists of 3 or 4 twists per inch are typical. Makers of traditional floss sold in conventional dispensers have found consumers prefer softer flosses that slide more easily between teeth and are gentler on gums. For this reason, manufactures have reduced or eliminated twist in such multifilament yarns. However, this typically results in an increase in fraying and breaking. In order to maintain reduced fraying and breaking, manufactures have impregnated the space between fibers with soft polymers such as microcrystalline wax or beeswax.
While coated multifilament yarns are suitable for use when dispensed from a conventional floss dispenser, where the floss is wrapped around a spool, wax coated multifilament flosses are not known to be used in commercial single-use floss devices as described above. This is due, in part, to difficulties associated with the manufacture of such devices using wax coated multifilament yarns.
In summary, there is a need for a single-use flossing device that uses flosses that slide more easily between teeth and are gentler on gums, while maintaining strength to reduce fraying and breakage, as well as methods and apparatus for making such single-use devices. As described below, it now has been discovered how to provide single-use flossing devices using wax coated dental floss.